Generally, gas cylinder actuators are part of equipment for locking a metal sheet adapted to be shaped in a press or worked with another pressing system, for blanking or drawing, and are used to extract or retain the metal sheet during its working.
Usually, in this type of work and when using these pressing systems, oils or other emulsifying liquids are used abundantly in order to improve work.
However, while these oils or similar liquids fully perform their task of improving sheet metal working, they often damage the gas cylinder actuators, which are also fitted within the die.
The oil in fact penetrates the gas cylinder actuators, passing through the gasket, entrained by the moving stem; this condition creates problems in terms of durability of the gas cylinder actuator, since it compromises its tightness with respect to the pressurized gas.
In order to obviate this drawback, protective domes are known which can be made of various materials, depending on the aggressive agents from which the associated gas cylinder actuator is to be protected, and must be fixed so as to cover part of the body of the gas cylinder actuator on the stem side, which is the part that is most subject to being splashed by the oils and fluids that fall from the overlying metal sheet being worked.
These domes have a passage hole for the work strokes of the stem, and therefore, although they achieve the task of protecting the body of the gas cylinder actuator, they do not protect sufficiently the gaskets between the body and the stem, since the aggressive liquids penetrate between the hole of a dome and the stem that passes through it and reach the dynamic seals between the body and the stem of the gas cylinder actuator.